Research On Modeling And Control Of Large Valve Quick Opening System

Large valve quick opening control system is generally used in the large equipment of aerospace,oil,power and other fields.Its common control methods are: heavy hammer type relief valve,diaphragm type relief valve and self compound relief valve,etc.These methods need to replace the release film,which is time-consuming and laborious.In order to work continuously,in this paper,the design and simulation of the large valve quick opening system was carried out based on the background of increasing and decreasing pressure in the orbital cabin during the operation of the spacecraft.Firstly,large-diameter pipeline valve was taken as the research object,in order to realize the function of rapid increasing and reducing pressure,a large-scale valve quick opening system was designed,and the parameters of each component in the system were calculated and selected.The model of the proportional relief valve in the quick opening system was built and its parameters were optimized.The accuracy,rapidity and stability of the proportional relief valve were improved.Then,different opening degrees of the large valve and the load of the system were taken as the research object,the simulation model of large valve quick opening system was established in AMESim software,the performance of the control system with proportional directional valve and proportional speed control valve was studied respectively.Under the PID control,the control system of large valve with different opening was simulated,and the control scheme achieving the requirements of system pressure increase and decrease was determined through comparative analysis.Finally,in order that the total pressurization time of large valve quick opening system can achieve the requirements of the system,according to the simulation results of different valve opening,the fuzzy rules of fuzzy PID control were established,and the fuzzy PID control was used to study the fast opening system of proportional directional valve.The results show that: The optimized parameters of the proportional relief valve were suitable for the system;The simulation results of the fast opening system show that the fast opening system with proportional directional valve is better than that with proportional speed control valve;Under the fuzzy PID control,the pressure reducing performance of the system is the best when the valve opening is 70°.The pressure reduction time of the system under the changing load condition is less than that under the certain load condition.When the opening is 75°,the system has the best performance of increasing pressure.The time for the system to increase pressure under changing load is less than that under certain load.The system can steadily and accurately complete the pressure increase and decrease of the system in 15 seconds,It can supply oxygen and keep pressure for spacecraft quickly,and ensure the safety of astronaut’s working environment.